D4 is a bit too far if i know anything about your tastes, Neven. I'm a bit surprised you're looking anything further than D3, at this time.
I've always posted the D1-D6 forecast. Why would I do that if I don't look beyond D3? Of course, the forecast becomes more unreliable the further out you go, which is why I almost never post anything beyond D6.
So, are you trying to figure out if that D4 could in fact develop into something stronger as we get closer?
No, I'm not trying to figure that out. I would think the ECMWF model is better at it than I am. I'm only seeing a short-lived plunge to 979 hPa, which is not nothing, but it's not anything like a GAC yet either. Maybe that will change in the next run, but probably not by much.
Do you have your guts feeling conditions favorable to GAC devastation start to form up? In other words, i'm just curious how you'd estimate likelyhood of any serious August GAC event, at this time.
I think a GAC like we saw in 2012 or last year is always possible now.
As I wrote back in 2012 on the ASIB:
I'm hesitant calling this the Great Arctic Cyclone of 2012, or Arcticane, or some such. What if we see a similar cyclone in 2013 or 2014? We'll run out of names.
Mind you, I don't want to downplay the importance and magnitude of this storm, it's by far the biggest thing I have seen in the Arctic since I started the blog, but to me this whole event isn't about the storm itself, but about a possible new regime - a new aspect of the new abnormal - with big summer storms in the middle of the Arctic. Or who knows maybe next time a bit closer to the coast.
Whether we have a GAC this year, I don't know. It's certainly possible.
But I'm not that into forecasting, as much as I'm into analysing what's going on. Which is why I said I'd rather not see a GAC muddy the water, but just observe how much ice will melt out anyway without ice-destroying weather. That's looking at it from the analysis-POV.
Of course, if we do get a GAC, it will be spectacular. And that'd be pretty cool, from the spectacle-POV.
Looking from the consequences-POV, everything sucks. There is no good news whatsoever, except perhaps for Greenland.